Added "touch" command

Enables:

- Creation of nodes
- Modification and removal of node properties

This command could I guess also encompass adding and removing mixins.

````
$ ./bin/phpcr phpcr:touch /foobar-123                                      
Creating node:  /foobar-123 [nt:unstructured]
````

````
$ ./bin/phpcr phpcr:touch /foobar --type=nt:unstructured --set=bar=myvalue --unset=foo --dump --set=dtl=ltd 
Node at path /foobar already exists and has primary type nt:unstructured.
 > Setting property bar to myvalue
 > Setting property dtl to ltd
 > Unsetting property foo
Node dump: 
 - bar = myvalue
 - jcr:primaryType = nt:unstructured
 - dtl = ltd
````